1. Field of the Invention
The field of the invention is contaminant oxidation, or, more specifically, oxidizing solutions and processes for oxidizing contaminants.
2. Description of Related Art
The appearance of contaminants, such as hydrocarbons, organics, bacteria, algae, animal oils, vegetable oils, and arabic gums, in various media and on various surfaces, creates a need for effective contaminant removal materials and techniques.
For example, a typical surface water storage facility can be expected to encounter hydrocarbon contaminants in tank bottom materials, and in emulsified layers on the stored water. Similarly, cooling tower installations are known to encounter hydrocarbon based oil layers on water that has accumulated in an adjacent basin, as well as, in the sludge at the basin bottom. Algae will frequently appear in the cooling tower to compound the contamination problem. Hydrocarbon contaminants are also known at crude oil storage tanks which frequently have contaminated soil surfaces proximate the tank, and at wastewater treatment plants, which are often faced with hydrocarbon based grease layers at their lift stations, and undesirable bacteria in their aeration tanks.
Organics, including animal oils and vegetable oils, are a known contaminant on surfaces, such as sidewalks and parking lots near restaurants and other public establishments. Sidewalks are also subjected to contamination with arabic gum.
The prior art includes various oxidizing materials, solutions and processes, as well as, various contaminant remediation methods.
U.S. Pat. No. 6,423,868 is a process for the production of an aqueous monoester peroxycarboxylic acid solution by reaction of a peroxygen compound with at least one dicarboxylic acid and with at least one alcohol optionally in the presence of an acid catalyst. Aqueous monoester peroxycarboxylic acid solution is obtainable by this process. Use of the aqueous monoester peroxycarboxylic acid solution is as a disinfectant. A microbicide is described in the description as a monester percarboxylic acid prepared by reaction between a monoester of an aliphatic dicarboxylic acid and hydrogen peroxide.
U.S. Pat. No. 6,423,236 relates to a method for treating waste water including the steps of: oxidizing the waste water, and then treating the oxidized waste water with a reverse osmosis membrane having high salt rejection rate. By being treated with the reverse osmosis membrane, the waste water is separated into an impermeated liquid which contains an oxidizable substance, and a permeated liquid which contains almost no oxidizable substance. Oxidation by hydrogen peroxide is mentioned.
U.S. Pat. Nos. 6,245,729, 6,384,006, and 6,319,888 include a system for forming and releasing an aqueous peracid solution is disclosed. The system includes a container and a peracid forming composition provided within the container. The container is permeable to the passage of water and aqueous peracid solution. The peracid forming composition includes a peracid precursor and a peroxygen source. Preferably, the peracid forming composition includes a chemical heater capable of releasing heat upon hydration. When placed in water, water enters the container and interacts with the peracid forming composition provided within the container. The water combines with the peracid precursor and peroxygen source to provide an aqueous peracid composition. The presence of a chemical heater within the container provides for the generation of heat within the container which enhances the rate of peracid formation. The peracid solution leaves the container and forms an effective sanitizing amount of sanitizer. A composition for forming and releasing an aqueous peracid solution is disclosed. The composition can include a mixture of peracid forming components or a composite structure containing peracid forming components adhered together. Methods of sanitizing a surface having a population of microorganisms are provided, and methods for manufacturing are provided.
U.S. Pat. No. 5,296,239 provides peracetic acid compositions containing at least one thickening agent and optionally a stabilizer chosen from sequestering agents, free-radical scavengers and mixtures containing two or more of these products. The preferred compositions are obtained by successively incorporating at least one stabilizer and then at least one thickening agent. These compositions are especially capable of being employed for the disinfection of large bulks which are difficult to immerse and of nonhorizontal surfaces, and for detergency or bleaching at low temperature.
U.S. Pat. No. 5,736,497 provides a phosphorus-free and boron-free cleaning composition containing a phosphorus-free aqueous solution containing an active ingredient (e.g., hydrogen peroxide or a compound capable of releasing hydrogen peroxide under the conditions prevailing in use of the composition), at least one organic stannate which is a tetravalent tin complexed with dicarboxylic acid, hydroxy carboxylic acid, or tricarboxylic acid, and optionally at least one organic stabilizer which is a benzoate, a sulfonic acid or salt, or mixtures thereof. The active ingredient is hydrogen peroxide or a percarbonate. The aqueous solution has an alkaline pH.
U.S. Pat. No. 4,051,058 provides Stable peroxy-containing concentrates useful for the production of microbicidal agents consisting essentially of 0.5% to 20% by weight of peracetic or perpropionic acid or their precursors, 25% to 40% by weight of H.sub.2 O.sub.2, 0.25% to 10% by weight of an organic phosphonic acid capable of sequestering bivalent metal cations and their water-soluble acid salts, 0 to 5% by weight of anionic surface-active compounds of the sulfonate and sulfate type, the remainder being water.
U.S. Pat. No. 4,051,059 provides Peroxy-containing concentrates, stable in storage, useful for the production of functional agents consisting essentially of 0.5% to 20% by weight of peracetic or perpropionic acid or their precursors, 25% to 40% by weight of H.sub.2 O.sub.2 0 to 5% by weight of anionic surface-active compounds of the sulfonate and sulfate type, the remainder being water.
U.S. Patent Application No. 20020086903 provides synergistic biocidal oxidant, useful as a sanitizer and disinfectant, is disclosed. The synergistic biocidal oxidant comprises a lower organic peracid, preferably peracetic acid, and chlorine dioxide.
U.S. Pat. No. 5,525,008 provides a method and apparatus for in-situ treatment of soil and groundwater contaminated with organic pollutants. The process involves defining the nature and extent of the contamination; determining the hydrology and geology of the contaminated area; determining the volume and concentration of a reactive solution required to effect treatment of the contaminated area; injecting the reactive solution into one or more injectors that are inserted into the ground, sealed and positioned so as to assure flow of the reactive solution through the contaminated area; allowing the reactive solution to flow through the contaminated area thereby reacting chemically with the contaminants contained within the contaminated area; and determining when the treatment is complete by monitoring by-products of the chemical reaction. Preferably, the reactive solution is an aqueous solution of hydrogen peroxide and metallic salts.
U.S. Pat. No. 5,820,761 involves a process wherein organic pollutants in wastewaters are wet-oxidized by addition of pure oxygen or an oxygen-containing gas at temperatures of 80.degrees to 330 degrees C., under pressures of 1 bar to 200 bar and at a pH value below 7. For the wet oxidation process, iron ions and digested sludge or surplus sludge from a biological sewage treatment plant are added to the wastewater.
U.S. Pat. No. 6,387,278 relates to in situ hydrous pyrolysis/partial oxidation of organics at the site of the organics constrained in a subsurface reservoir produces surfactants that can form an oil/water emulsion that is effectively removed from an underground formation. The removal of the oil/water emulsions is particularly useful in several applications, e.g., soil contaminant remediation and enhanced oil recovery operations. A portion of the constrained organics reacts in heated reservoir water with injected steam containing dissolved oxygen gas at ambient reservoir conditions to produce such surfactants.
U.S. Pat. No. 6,036,849 includes a method of removing hydrocarbons from soils contaminated with various hydrocarbons such as gasoline, diesel fuel, solvents, motor oil and crude oil. The process first screens the soil to remove oversized rocks and debris and to reduce the contaminated soil to uniformly sized particles. The soil particles are moved along a conveyor and first sprayed with an oxidizer diluted with ionized water and then sprayed with only ionized water. The washed particles are then vigorously mixed with their entrained oxidizer and ionized water in an auger mixer for several minutes to oxidize almost all of the remaining hydrocarbons. The washed and hydrocarbon-free soil is then moved by conveyor to a stockpile for storage, testing and drying.
U.S. Pat. No. 6,398,938 includes a process, which includes: electrochemically oxidizing at least one organic compound by bringing the organic compound into contact with an anode, wherein the anode includes: an electrically conductive support; and an electrically conductive, anodically polarized layer on the support; wherein the anodically polarized layer is formed in situ upon the support by precoating; and wherein the organic compound is not phosphonomethyliminodiacetic acid. Another embodiment of the present invention provides a product, produced by the above process.
U.S. Pat. No. 5,948,275 is an integrated method for purifying industrial and/or urban effluents containing a large amount of organic material in solution and/or suspension, wherein said effluents are treated in a wet oxidation reactor. The effluents are oxidized in the presence of at least one oxidizing gas to mineralize a large part of the organic material therein by producing a gas phase and an essentially liquid phase mainly containing soluble residual organic material, as well as an essentially inorganic solid phase in suspension. The essentially liquid phase from the reactor is subjected to liquid/solid separation to separate the solid phase, and at least a fraction of the separated solid phase is recycled in the wet oxidation reactor. Various alternative embodiments of the method include adding a catalyst and/or an agent for acidifying the recycled solid phase fraction. The facility may operate continuously or semi-continuously between interruptions.
U.S. Pat. No. 6,453,914 includes a method for removing organometallic and organosilicate residues remaining after a dry etch process from semiconductor substrates. The substrate is exposed to a conditioning solution of phosphoric acid, hydrofluoric acid, and a carboxylic acid, such as acetic acid, which removes the remaining dry etch residues while minimizing removal of material from desired substrate features. The approximate proportions of the conditioning solution are typically 80 to 95 percent acetic acid, 1 to 15 percent phosphoric acid, and 0.01 to 5.0 percent hydrofluoric acid.
U.S. Pat. No. 6,395,188 is a single step wet oxidation process for treating wastewaters containing organic species, with or without heteroatoms, and anions of strong acids, e.g. sulfate or phosphate ion, or cations of strong bases, e.g., sodium, potassium or calcium ions, and which may contain ammonium ion and/or nitrate ion in addition to added ammonium ion and/or nitrate ion was developed which on thermal treatment near the critical temperature of water removes substantially all the COD and nitrogen through conversion to water, carbon dioxide or carbonate species, nitrogen gas and small amounts of nitrous oxide. Key to the success of the process is the balancing of all reducing species with an equivalent amount of oxidizing species and the balancing of all strong acid anions with strong base cations and including at least 0.06 acetate ion for moles of nitrate in the wet oxidation process.
U.S. Pat. No. 6,426,020 is an etchant for copper or copper alloys comprising 5–50 wt % of an alkanolamine, a copper ion source in the amount of 0.2–10 wt % as copper, a halide ion source in the amount of 0.005–10 wt % as halogen, 0.1–30 wt % of an aliphatic carboxylic acid, and the balance water, wherein the molar ratio of the alkanolamine to one mol of the aliphatic carboxylic acid is two or more. The etchant is free from problems such as instability of the liquid composition and unpleasant odor, has a high etching rate, exhibits only very slight corrosion even if a small amount of residue is left on the surface and is capable of producing a roughened surface when used for microetching.
While the foregoing may function generally with respect to the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described. For example, such compositions and processes do not provide what is needed, that is effective oxidizing solutions and processes for safely oxidizing the above-described contaminants in a wide variety of locations and media in which they are encountered.